oddball, maybe i can help you here, so you don't have to go thru this again. first, i must say i feel for you, but in a way you allowed this to happen which in turn won't help you or the dear/hh population attain the appropriate service needed.
as a consumer one should always know what the name of the business or agency that is providing one with any service. that way if a problem arises, such as yours it can be fixed.
second, it's quite possible a "certified" interpreter may not of met your needs. maybe before the appointment next time request an interpreter that has experience in medical interpreting. that interpreter wasn't at fault for being"non certifified" it sounds like the terp simply didn't have the skills for any setting period. the owner of the agency should have been aware of your strong ASL needs and sent an interpreter that can sign ASL and has knowledge in the medical field. don't be so nice because you don't want anyone messing up when it comes to your health. you sound real nice, but in this situation i feel you should have been more firm. be careful out there, i hoped this helped a bit.
i'm disappointed this interpreter didn't make an immediate call for a replacement. i am an interpreter and can sign ASL, PSE, and SEE, but ther has been times when i tell my client" hey i can't meet your needs, so let me call my boss and possibly get you a different interpreter." professionalism is important in all fields. good luck